I. Source of the Aqua Appia, in a very ancient Stone-quarry of the time of the Kings, on the bank of the river Anio. II. Source of another Spring of the Aqua Appia in another ancient Stone-quarry, (near to the former). III. 1. THE AQUEDUCTS ABOVE SUBIACO. 2. —— River Anio, the Upper Lochs. —— —— the third Loch and the Bridge over it. IV. 1. —— Anio Novus, the third Loch. 2. —— —— The Specus. V. —— Anio Novus—a Castellum Aquæ, and Line of the Specus cut in the cliff. VI. The Claudia, Anio Vetus, and Novus, and Marcia, in the Valley of the Arches below Subiaco and above Tivoli. VII. Two other Views of the Ruins of the Arcades of the Claudia and Anio Novus (in the Valley of the Arches above Tivoli). VIII. Aqueducts at Tivoli—Cascades of the Anio, with the Round Temple of the Sibyl at the top. IX. Aqueducts below Tivoli—The Marcia—a great Castellum Aquæ on the Via di Carciano, B.C. 145. X. Aqueducts below Tivoli—Aqua Marcia—Reservoir, or Castellum Aquæ. Views of the two chambers. XI. Aqueducts below Tivoli—1. Anio Novus—Castellum. 2. Marcia—Castellum rebuilt by Trajan. XII. The Claudia and Anio Novus in the Campagna of Rome, near Roma Vecchia, over the fine arcade, four miles from Rome. XIII. The Claudia and Anio Novus passing over the Marcia, Tepula, and Julia, at the Tor Fiscale, and view near the Porta Furba. XIV. 1. The Marcia on the bank within the wall of Aurelian, at the Porta Tiburtina. 2. Claudia and Anio Novus at the angle of the Sessorium. XV. Aqueducts at the Porta Maggiore— 1. Marcia, Tepula, and Julia, entering Rome, passing through the Wall. 2. Marcia, &c., within the Wall. XVI. 1. Claudia and Anio Novus over the Porta Maggiore. 2. Anio Novus on the Cœlian, over the arch of Dolabella. XVII. 1. Arches of Nero within the Porta Maggiore, crossing the great inner _fosse_ of the Sessorium on a double arcade. 2. Aqua Marcia within the Porta Maggiore, as shewn in an excavation in 1871. XVIII. 1. The Claudia and Anio Novus, in the North Wall of the Gardens of the Sessorium, now of S. Croce. 2. Nymphæum of Alexander Severus, where the trophies of Marius were hung. XIX. Great Reservoir on the Arches of Nero over the Arch of Dolabella, on the Cœlian. PLANS AND DIAGRAMS. PLATE I. Plan of the Sources of the Appia and Virgo, in the meadows of Lucullus, on the bank of the river Anio. II. The Appia at the Porta Capena, the specus passing through one of the towers of the Porta Capena, now a gardener’s cottage.